What happened? A worker was performing a routine laboratory procedure that requires the sterilization of a bacterial spreader by dipping in a small amount of ethanol followed by flaming with a standard Bunsen burner. After completing the experiment, the worker put the glass container of ethanol down near the burner and reached to turn off the gas. The worker heard a small pop as the ethanol vapors ignited. At first the worker waited for the ethanol to burn off. Then, they attempted to dilute the ethanol with what they thought was water from a plastic squirt bottle. However, the bottle actually contained more ethanol which fed the fire and ignited the plastic squirt bottle.
In panic, the worker ran towards the hall with the burning bottle in hand. The bottle started to melt and dropped burning ethanol onto paper bench materials, the floor and a sponge mop near the door. The worker dropped the burning bottle in the hall and yelled for help. A nearby co-worker became aware of the situation, pulled the fire alarm, retrieved a fire extinguisher and extinguished the fires. The worker sustained burn blisters on their middle finger.
Why did it happen? First, flammable chemicals were allowed too close to an open flame. Second, an unknown liquid (ethanol), also flammable, was inappropriately added to the fire. The squirt bottle of liquid was not labeled.
How can a similar occurrence be avoided? Flammable chemicals must be handled only in areas free of ignition sources (e.g. open flames, static electricity, burning tobacco, hot surfaces – Laboratory Chemical Safety Manual, section 1.9.1).
Panic never helps. Prevent panic by knowing the emergency procedures in advance of an emergency situation (Laboratory Chemical Safety Manual, section 1.8.3). Workers need to be aware that contained fires, such as an ethanol in a glass beaker, are easily snuffed out by placing a glass plate or other non-flammable material on top of the container. This starves the fire of oxygen. Class B extinguishers are used to extinguish uncontained flammable liquid fires. The agent used is normally dry chemical, carbon dioxide or halogenated agent. Water will normally only spread a flammable liquid fire and should not be used.
All hazardous chemicals must be properly labeled at all times. Non-hazardous substances which could be mistaken for a hazardous chemicals (e.g. water), must be labeled in order to avoid confusion in the workplace over which materials are hazardous and which are not (Chemical Management – Best Practices, section 2).
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